John Giuca (c.) with attorneys Andrew Stengel, left, and Mark Bederow was granted a retrial in the 2003 killing.

The man convicted in the “Grid Kid” killing of a Fairfield University football player in Brooklyn 13 years ago is getting a new trial.

A state appellate court sided with John Giuca Wednesday in his longtime bid to have another jury hear the evidence related to the 2003 murder of Mark Fisher, 19. Fisher was a Fairfield University football player who was shot and killed near Brooklyn’s Prospect Park, a few blocks from Giuca’s home, after a night of partying with Giuca and some friends in Manhattan.

Lawyers for Giuca, 33, who is currently serving 25 years to life in prison, argued that that Giuca should have his murder conviction overturned and receive a new trial because of unreliable testimony from one of the prosecutor's witnesses.

The argument centered around John Avitto, a cooperating witness, who Giuca allegedly confessed to the shooting while on Rikers Island.

Avitto, an admitted substance abuser and diagnosed bipolar schizophrenic, avoided up to seven years in prison for a 2004 robbery when a prosecutor placed him into a substance abuse program in exchange for his testimony at the 2005 trial.

Avitto recanted his testimony and apologized to Giuca at a hearing years later.

Mark Fisher was a Fairfield University football player who was shot and killed near Brooklyn’s Prospect Park.

(Murray, Ken)

Even so, a lower court denied Giuca's motion to overturn the conviction because of its belief there was insufficient proof of an agreement between Avitto and the prosecution.

Giuca was also convicted of robbery and criminal possession of a weapon.

“Prosecutors must not only disclose exculpatory for impeaching evidence but must also correct the knowingly false or mistaken material testimony of a prosecution witness,” the appeals court said in its ruling, adding that there was “a reasonable possibility that the prosecution’s errors affected the jury’s verdict.”

“It has taken 13 plus years too long, but justice finally has been served in this case,” said Giuca’s attorney, Mark Bederow.

John Avitto, 46, recanted his testimony and apologized to Giuca at a hearing years later.

(Jesse Ward/for New York Daily News)

“The trial was a disgrace and the trial prosecutor knew it was littered with false testimony and undisclosed material. We are ecstatic that the Appellate Division agreed and unanimously reversed this conviction in a strong opinion. We have every expectation that John will be home soon.”

A spokesman for the Brooklyn DA’s office did not immediately respond to a request for comment.